Upper respiratory tract infections (also called URT infections or URTI) are illnesses caused by an acute infection involving the upper respiratory tract: nose, sinuses, pharynx and/or larynx. The most common examples of URT infections are rhinitis, rhinosinusitis, nasopharyngitis, pharyngitis, epiglottitis, laryngitis, tonsillitis, laryngotracheitis, tracheitis, or combinations thereof.
URTI are often caused by viruses. Over 200 different viruses have been isolated in patients with URIs. The most common virus is called the rhinovirus. Other viruses include the coronavirus, parainfluenza virus, adenovirus, enterovirus, and respiratory syncytial virus.
The most common symptoms of upper respiratory tract infections are cough, sore throat, runny nose, nasal congestion, headache, low grade fever, facial pressure, sneezing, and combinations thereof. URT infections are usually associated with tiredness, discomfort and a loss of performance and concentration.
There can also be some complications associated with URT infections such as ear infection like otitis media and sometimes bronchitis.
All human can have URT infections. In particular children (including young children) are very likely to catch URT infections since they come into close contact with many other individuals, e.g., in school or in kinder garden.
Infants (i.e. babies from birth up to 1 year of age) are also prone to develop URT infections in view of their weak conditions and immature immune defences. However they will require a special attention since the consequences on their health of such diseases can be serious compared with other individuals.
Many attempts have been made to prevent URT infections. The use of probiotics has especially been investigated. Probiotics are considered to be viable microbial preparations which promote the individual's health by preserving the natural microflora in the intestine. Probiotics are deemed to attach to the intestine's mucosa, colonize the intestinal tract and likewise prevent attachment of harmful microorganisms thereon. A crucial prerequisite for their action resides in that they have to reach the gut's mucosa in a proper and viable form and do not get destroyed in the upper part of the gastrointestinal tract, especially by the influence of the low pH prevailing in the stomach.
For example WO2008042101 from Danisco provides methods for reducing respiratory disease in children, comprising: providing a culture of L. acidophilus; providing a child at risk of developing respiratory disease; and administering the culture of L. acidophilus to the child at risk, under conditions such that the risk of developing respiratory disease is reduced. However, adding live probiotic bacteria to products so that they remain viable until consumption is a non-trivial task. In particular for products with longer storage times this is difficult to accomplish and may require additional technical efforts. This invention targets young children who are preferably from 3 to 5 years old.
WO2012/062780 from Nestec S A disclosed composition comprising non-replicating probiotic micro-organisms for use in the prevention or treatment of upper respiratory tract infections and/or its symptoms. This composition can offer the probiotic benefits while being easy to prepare and to store without loss of activity.
Other pathways than probiotics have been explored such as the use of oligosaccharides, and especially human milk oligosaccharides. Human milk oligosaccharides (HMOs) are, collectively, the third largest solid constituents in human milk, after lactose and fat. HMOs usually consist of lactose at the reducing end with a carbohydrate core that often contains a fucose or a sialic acid at the non-reducing end.
There are approximately one hundred milk oligosaccharides that have been isolated and characterized in human milk, however this represents only a very small portion of the total number remaining to be characterized. Mother's milk is recommended for all infants. However, in some cases breast feeding is inadequate or unsuccessful for medical reasons or the mother chooses not to breast feed. Infant formulae have been developed for these situations. Fortifiers have also been developed to enrich mother's milk or infant formula with specific ingredients.
Several compositions have therefore been developed using HMO ingredients, such as fucosylated oligosaccharides, lacto-N-tetraose, lacto-N-neotetraose or sialylated oligosaccharides, and for different purposes.
For example WO2005055944 from Children's hospital medical center describes a pharmaceutical composition comprising a molecule comprising a fucose group in an al alpha-2 linkage, an alpha-3 linkage or an alpha-4 linkage to a galactose group and a pharmaceutically acceptable carrier. Various molecules are described such as 2′-fucosyllactose. This application is quite general since several infections can be prevented or treated, including respiratory or enteric infections, and there is a large target of patients (infants, children or adults).
Further studies were specifically focused on various associations of HMOs with either a probiotic strain or with other specific components.
For example WO2009/077352 from Nestec S A relates to a composition suitable in the prevention of opportunistic infections comprising a particular synergistic association of a probiotic Bifidobacterium with a fucosylated oligosaccharide. Respiratory tracts infections are cited amongst the opportunistic infections that may be prevented. This invention especially targets immune-compromised individuals such as preterm infants, older children or adults with an immune system which is not fully effective as a result of an existing condition or illness (e.g. HIV) or as a result of therapy for an existing condition e.g. Crohn's disease or rheumatoid arthritis or chemo-therapy for the treatment of cancer).
WO2009/112361 from Nestec S A relates to another composition suitable in the prevention of opportunistic infections comprising a particular synergistic association of a N-acetyl-lactosamine and/or an oligosaccharide containing N-acetyl-lactosamine with a probiotic Lactobacillus sp. Several conditions are cited such as pathogenic infections of the upper respiratory tract.
WO2012/092154 from Abbott refers to methods of using HMOs for improving airway respiratory health of infants, toddlers and children. However a wide list of HMOs is indicated in this application as well as several combinations of different HMOs. It is claimed that the composition seems to be efficient when HMOs are present with carotenoid.
WO2011/136648 from Nutricia is focused on the use of a composition comprising HMOs such as 2-fucosylated oligosaccharides for the preparation of a nutritional composition for feeding an infant, said infant having Lewis blood type Le(a−/b+) or Le(a−/b−) and/or Lewis blood type Le(x−/y+) or Le(x−/y−). However this application does not refer to the prevention and/or treatment of URT infections.
None of the previous work is therefore focused on the prevention and/or treatment of URT infections in infants or young children having higher risks of infections than the average, especially higher risks of catching URT infections. These infants and these young children represent a sub-group of subjects of a higher concern and who require a higher care than the other infants or young children since they will be more prone to get such diseases and the associated complications.
There is therefore a need for these infants at risk or these young children at risk to develop an efficient specific composition that will allow preventing and/or treating the URT infections.
There is also a need to deliver such health benefits in a manner that is particularly suitable for these young subjects (infants and young children), in a manner that does not involve a classical pharmaceutical intervention as these infants or young children are particularly fragile.
There is a need to deliver such health benefits in at risk subjects in a manner that does not induce side effects and/or in a manner that is easy to deliver, and well accepted by the parents or health care practitioners.
There is also a need to deliver such benefits in a manner that does keep the cost of such delivery reasonable and affordable by most.
Overall there is a need to deliver the most appropriate positive health effects to the specific sub-populations in needs, without unnecessarily targeting broad and large populations.